Academic underachievement frequently is associated with attention-deficit/hyperactivity disorder (AD/HD); however, the role of variables beyond AD/HD symptoms and cognitive mediators is unknown. Further, whether prediction models vary (a) relative to non-AD/HD students, (b) between math and reading, and (c) based on how achievement is defined has not been examined. Multiple measures (e.g., teacher ratings and behavior observations) were examined as predictors for concurrent achievement outcomes (standardized achievement test scores and report card grades) in math and reading in two samples of 1st through 4th grade children (136 with AD/HD, 53 without AD/HD). Teacher perceptions of academic skills were the strongest predictors of achievement test scores for both groups, while academic skills and enablers accounted for reading report card grades in children with AD/HD but not their normal counterparts. Implications of these findings for school-based assessment and intervention for students with AD/HD are discussed.